test(app): destroy a surface from its input event callback

The test pushes two key events into a Wayland surface's queue. The
first event's callback destroys the surface. The run must end cleanly,
without delivering the second event. Before 71091ca, ASan reported a
heap-use-after-free in app_runner_dispatch_input_events. The test
skips when WAYLAND_DISPLAY is unset.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 60 insertions, 0 deletions

diff --git a/tests/wayland/test_app_input.c b/tests/wayland/test_app_input.c
new file mode 100644
index 0000000..24b8b64
--- /dev/null
+++ b/tests/wayland/test_app_input.c
@@ -0,0 +1,60 @@
+/* An input event callback that destroys its own surface. The app runner
+ * must not touch the surface's entry after the callback, and must not
+ * deliver the surface's remaining input. Needs a Wayland compositor. */
+#include "wayland/internal.h"
+#include "yasl/app.h"
+
+#include <assert.h>
+#include <stdlib.h>
+
+struct test_state {
+    int keys;
+};
+
+static void push_key(struct yasl_surface *s)
+{
+    struct yasl_input_event ev = {
+        .surface = s,
+        .kind = YASL_INPUT_KEY,
+        .key = { .key = YASL_KEY_A, .action = YASL_KEY_PRESS },
+    };
+    assert(input_queue_push(&((struct wayland_surface *)s)->input, &ev));
+}
+
+static int on_init(void *ud, struct yasl_display *d)
+{
+    (void)ud;
+    struct yasl_surface *s = yasl_surface_create_toplevel(d,
+        &(struct yasl_surface_spec){ .title = "App Input Test", .size = {64, 64} });
+    assert(s);
+    push_key(s);
+    push_key(s);
+    return YASL_APP_CONTINUE;
+}
+
+static int on_event(void *ud, const struct yasl_event *ev)
+{
+    struct test_state *state = ud;
+    if (ev->type == YASL_EVENT_KEY) {
+        state->keys++;
+        yasl_surface_destroy(ev->surface);
+    }
+    return YASL_APP_CONTINUE;
+}
+
+int main(void)
+{
+    if (!getenv("WAYLAND_DISPLAY"))
+        return 77;
+    struct test_state state = {0};
+    int res = yasl_run(&(struct yasl_app_desc){
+        .app_id = "org.yasl.test.app-input",
+        .backend = YASL_BACKEND_WAYLAND,
+        .userdata = &state,
+        .init = on_init,
+        .event = on_event,
+    });
+    assert(res == 0);
+    assert(state.keys == 1);
+    return 0;
+}